Multiple sclerosis (MS) is an autoimmune neurodegenerative disease, which is marked by inflammation within the central nervous system with lymphocyte attack against myelin produced by oligodendrocytes, plaque formation and demyelination with destruction of the myelin sheath of axons in the brain and spinal cord, leading to significant neurological disability over time. The disease frequently occurs in young adults between 20-40 years of age, is more prevalent in females than males (2:1), and has a characteristic geographical distribution—estimated prevalence in the USA is 120/100,000 individuals (250,000 to 350,000 cases).
The diagnosis of MS is still defined primarily by clinical terms and relies on a combination of history, neurological examination and ancillary laboratory and neuro-imaging studies. Typically, at onset an otherwise healthy person presents with the acute or sub acute onset of neurological symptomatology (attack) manifested by unilateral loss of vision, vertigo, ataxia, dyscoordination, gait difficulties, sensory impairment characterized by paresthesia, dysesthesia, sensory loss, urinary disturbances, diplopia, dysarthria or various degrees of motor weakness. The symptoms are usually painless, persist for several days to a few weeks, and then partially or completely resolve. For the period following the first attack, the patient is defined to suffer from “probable MS.” Probable MS patients may remain undiagnosed for “definite MS” for years. After this variable period of remission, generally a second attack will occur, after which the diagnosis of “clinically definite MS” (CDMS) is made.
Laboratory tests for MS include: 1) cerebrospinal fluid (CSF) evaluation of IgG synthesis, oligoclonal bands; 2) MRI of the brain and spinal cord and; 3) exclusion of other autoimmune diseases by blood tests (e.g.; serum B12 level; HTLV 1 or HIV 1 titers; sedimentation rate or C-reactive protein; RA latex (Rheumatoid arthritis); ANA, anti-DNA antibodies (systemic lupus erythematosus). More recently, diagnostic criteria for CDMS have incorporated radiological assays, however, accurate diagnosis and prognosis in the “probable” stage, and early relapsing-remitting stages remains problematic. For example, it has been shown that positive MRI findings in the first demyelinating attack only provide a 50% successful prediction of development of clinically definite MS within 2-3 years. Likewise, detection of oligoclonal IgM bands in patients with early symptoms were only partially predictive of development of clinically definite MS.